Telescoping blade switch



June 2" 1959 I R. H. ALBRIGHT 2,889,435 TELESCOPING BLADE SWITCH I FiledMay 22, 1957 4 Sheets-Sheet 1 W VQ/M; BY

June 2, 1959 R. H. ALBRlGHT TELESCOPING BLADE SWITCH 4 Sheets-Sheet 2Filed May 22, 1957 INVENTOR. ia fl flzie/w/r BY 7% June 2, 1959 R. H.ALBRIGHT TELESCOPING BLADE SWITCH 4 Sheets-Sheet 5 Filed May 22', 1957June 2, i959 R. H. ALBRIGHT TELESCOPING BLADE SWITCH Filed May 22, 1957v 4 Sheets-Sheet 4 NVENTOR. fldyji 191 6/9/6797 q kw igg StatesTELESCDPING BLADE SWITCH Roy H. Albright, Grcensburg, Pa., assignor toI-T-E Circuit Breaker Company, Phiiadelphia, Pa., a corporation ofPennsylvania Application May 22, 1957, Serial No. 660,920

Claims. (Cl. 200-163) This invention relates to electric switches usedin high current and high voltage applications and more particularly toan electric switch wherein the operating force therefore is transmittedthrough a rotating insulator to move the switch blade along itslongitudinal axis, which coincides with the longitudinal axis of theterminating conductor, to effect circuit opening and closing.

In isolated phase bus, metal enclosed switchgear, and certain indoorapplications space is at a premium. At the present time the conventionalmethods of breaking the circuit, in such equipment, comprise a pivotedblade or a blade that is moved transverse to its own axis to produce adouble break. Therefore, equipment must be constructed with largeunoccupied spaces through which the blades will travel during operationof the switches.

This invention provides a blade which is moved along its longitudinalaxis to telescope within one of the terminating conductors therebyachieving a large saving in space. The telescoping blade switch lendsitself to high current applications as it permits the use of more highlyefiicient tubular conducting members for blades than the conventionalswitches using bar type blades. The telescoping blades permit the use ofmultiple contacts on the outer surface of the blades to provide auniform and effective current distribution. Inasmuch as the blade mayhave essentially the same contour as the conductors, the blade will havean equalized current distribution. Furthermore, this switch is adaptablefor high voltage applications since the parts can be effectivelyshielded to approach a uniform electrostatic field which is essentialfor high dielectric characteristics.

Movement is imparted to the blade by means of an operating mechanismcomprising a pinion gear which is in operative engagement with a racksecured to the blade. A rotatable insulator is interposed between thepinion gear and the switch actuating means which may be hand or poweroperated.

The rack and pinion require very little space. In fact, in the case ofisolated phase bus, with its large hollow conductors, the rack andpinion will mount inside the conductors and the entire switch will mountinside an enclosure of the same dimensions as the bus housing. Forsmaller sized conductors the pinion will be mounted outside of the bladeand cooperate with a rack mounted on the inner surface of the blade.

Operational force requirements are very low which reduces the stresseson the rotatable insulator. Furthermore, the insulator is not subjectedto a cantilever load but rather to a torsional load which it is betterable to withstand.

Accordingly, a primary object of this invention is to provide anelectric switch for high current and high voltage application which doesnot require additional space for blade movement during operation of theswitch.

Another object is to provide an electric switch having a telescopingblade operated by means of a rack and pinion.

Still another object is to provide an electric switch having atelescoping blade operated by means of a rack and pinion wherein thepinion is driven through a rotatable insulator.

A further object is to provide an electric switch having a telescopingblade operated by means of a rack and pinion both mounted within theblade.

Still another object is to provide an electric switch having atelescoping blade operated by means of a rack and pinion wherein therack is mounted on the blade and the pinion is mounted outside theblade.

Yet another object is to provide an isolated phase bus having atelescoping blade switch wherein the blade is operated by means of arack and pinion both mounted inside the blade and the pinion is drivenby a rotatable insulator positioned between the bus housing and hollowbus bar.

These objects and other objects will readily become apparent afterreading the following description of the accompanying drawings in which:

Figure 1 is a side elevation of a switchgear enclosure wherein thetelescoping blade switch may be mounted.

Figure 2 is a section through line 2-2 of Figure 1 looking in thedirection of arrows 2-2.

Figure 3 is a longitudinal section of a telescoping blade switch havingthe actuating pinion mounted externally of the blade. In Figure 3 theswitch is open.

Figure 4 is a view similar to that of Figure 3 with the switch closed.

Figure 5 is a section, reduced in size, through line 55 of Figure 3looking in the direction of arrows 55.

Figure 6 is a section, reduced in size, through line 66 of Figure 3looking in the direction of arrows 66.

Figure 7 is a longitudinal section of another embodiment of thetelescoping blade switch.

Figure 8 is a section through line -8 8 of Figure 7 looking in thedirection of arrows 8-8.

Figure 9 is a section through line 9-9 of Figure 7 looking in thedirection of arrows 9-9.

Figure 9a is a transverse section of isolated phase bus having atelescoping blade switch.

Figure 10 is a section through line iii-10 of Figure 7 looking in thedirection of arrows 1(l10.

Referring more particularly to Figures 1-6, switchgear enclosure 10 isprovided as a setting for the first embodiment of this invention.Balcony 97, reached by stairway 96, encircles enclosure 10' about midwaybetween the top and bottom thereof. Upper 99 and lower 98 access doorsprovide convenient entrance to the interior of enclosure 10' formaintenance purpose. Hand operated mechanism 11, mounted near groundlevel to the outside of enclosure it acts through rotating linkages 12,through 19 and directional gear boxes 20 and 21 to simultaneouslyoperate three identical switches 22.

For the sake of simplicity, only one switch 22 and its coupling to itsassociated directional gear box 20 shall be described, it beingunderstood that the other ganged switches 22 are substantiallyidentical. Switch 22 comprises a jaw structure 24 mounted on a firstconductor 25, a contact structure 26 mounted on a second conductor 27,and a movable blade 28 which is slidably positioned within contactstructure 26. Conductors 25 and 27 are positioned in axial alignmentwith a gap therebetween which is bridged by blade 28 when the switch 22is in a closed position (Figure 4).

Contact structure 26 comprises a housing 32 which has mounted thereincontact fingers 33 which are'arr-anged in circular fashion to be inwiping contact with the outer surface of blade 28. Garter springv 34provides'a' biasing force to urge fingers 33 against blade'28.Housing'32i is secured to hollow conductor 27 by means of bolts 31,which also pass through flanges 30 of clamp 29 which is secured to theend of conductor 27. Pinion 35 is positioned in housing 32 and ismounted for rotation on shaft 36 with teeth 35 being in operativeengagement with longitudinal gear rack 37 on the outer surface of blade28.

law structure 24 is secured to hollow conductor 25 at the end thereof bymeans of bolts 38 which pass through flange 39 of clamp 40 which issecured to the end of conductor 25. It is to be noted that blade 28, jawstructure 24, and conductors 25, 27 are axially aligned.

When pinion 35 is rotated clockwise with respect to Figure 3, plate 28Will be projected from housing 32 into engagement with jaw structure 24as in Figure 4. law structure 24 includes a tapered guide means 41 atthe entrance thereof to guide blade 28 between the circular arrangedcontact fingers 42 which are biased toward the longitudinal axis bygarter spring 43 into engagement with the outer surface of blade 28.Thus, an electrical path is completed between hollow conductor 25through the contact fingers 42 of jaw structure 24, blade 28, contactfingers 33 of contact structure 26 to the hollow conductor 27. If switch22 is mounted with the longitudinal axis of conductors 25, 27 in avertical position with conductor 27 positioned below conductor 25, aspring 44 is provided to counterbalance the weight of blade 28. One endof spring 44 rests against abutment 45 which is welded or otherwisesecured to conductor 27 and the other end of spring 45 rests againstmember 46 which is wedged into blade 28 thereby biasing blade 28 upwardand in this manner lessens the force required to operate switch 22 toits closed position and the force required to maintain blade 28 in itsprojected position.

A rotating insulator 50 serves as the operative connection betweenrotating linkage 20 and pinion shaft 36. Inserts 51 and 52 project fromends 53, 54 respectively of insulator 50 and are secured thereto bymeans of die metal recess linings 55. Pin 57 secures insert 52 tocoupling 56 which is secured to shaft 36 by means of said screws 58while pin 59 secures insert 51 to coupling 60 which is joined to outputshaft 61 of gear box 20 by means of key 62 and screw 63.

Shaft 64 of gear box 20 is driven by one of the rotating linkages 14-49having splined ends (not shown) which mate with internal formations 64'to thereby drive bevel gear 65. Bevel gear 65 mates with a second bevelgear 66 keyed to output shaft 61 to thereby rotating insulator 50 whichin turn rotates pinion shaft 36 to drive pinion 35 and operate switch22.

When switch 22 is closed, blade 28 bridges the gap between jaw structure24 and contact structure 26. To move switch 22 to its open position ofFigure 3, pinion 35 is rotated counter clockwise with respect to Figure3. Pinion 35 being in engagement with rack 37 will move blade 28longitudinally to the right with respect to Figure 4 so that ittelescopes within conductor 27 and once again a gap is formed betweenjaw structure 24 and contact structure 26.

Referring more particularly to Figures 7-10, the second embodiment ofthis invention is illustrated as switch 100 which is connected as adisconnect switch for isolated phase bus of a type described in detailin copendlng application Ser. No. 353,301, filed May 6, 1953 andassigned to the assignee of the instant invention. Briefly, isolatedphase bus comprises a hollow conductor 101 centered within a housing 102and insulated therefrom by means of insulators 103. Hollow conductor 101is large enough to permit pinion 105 to be mounted therein. Contactstructure 106 is secured to the end of hollow conductor 101 at flangemember 101 and a jaw structure (not shown) similar to jaw structure 24of Figures 3 and 4 is secured to a second isolated phase conductor (notshown) which is in longitudinal alignment with conduc- 4 tor 101. A gapbetween the jaw structure and contact structure 106 will be bridged byswitch blade 107 when switch 106 is in its closed position.

Contact structure 106 includes a housing 108 inside of which concaverollers 109 are rotatably mounted on shafts 109. Rollers 109 areprovided since the great weight of blade 107 makes a sliding bearingcontact impractical. Resilient contact fingers 119, which are secured tothe outside of housing 108, have the free ends thereof extending throughopenings in housing 108 into wiping contact with blade 107. A rack 104is secured to the inside of blade 107 together with strengtheningmembers 108 which are positioned adjacent to longitudinal slots 129 andprovide additional support for the walls of blade 107.

Pinion 105 is mounted on shaft 110 which is journalled in bearings 111of contact structure housing 108. Pin 112 couples shaft 110 to rotatableinsulator 103a, which extends from contact structure housing 108 toisolated phase bus housing 102. Rotatable insulator 103a is ofsubstantially the same design as rotatable insulator 50 of Figure 2 andmay be used to replace one of the insulator supports 103 in the regionof switch 100. A stub shaft 113 extends from the housing end ofrotatable insulator 103a and is later connected to the actuating means(not shown) for switch which may be of the same construction as theactuating means for switch 22.

It is to be noted that by mounting the rack 104 and pinion within theblade 107, the size of housing 108 may be substantially equal to thesize of conductors 101 thereby providing a substantially uniform currentdistribution. In the same manner, isolated phase bus housing 102 neednot be mis-shapened over the area into which blade 107 telescopesthereby simplifying electrostatic shielding at high voltages.

Although the present invention has been described with an exemplaryform, it is to be understood that variations may be made within thebroader spirit and scope of the invention, and it is not intended to belimited except as set forth in the following claims.

I claim:

1. An electric switch comprising a first structure, a second structure,a hollow elongated blade; said structures being fixed in axial alignmentwith a gap therebetween; said blade being disposed within said firststructure and slideable along the axis thereof; said switch having aclosed position wherein said gap is bridged by said blade and an openposition wherein said gap is open; a rack secured to said blade and apinion in operative engagement with said rack to move said blade alongits axis and thereby operate said switch between said open and closedpositions; said rack being positioned between the ends of said blade;both said rack and said pinion being disposed within said blade; saidpinion having its axis of rotation positioned perpendicular to thelongitudinal axis of said blade; said blade having a longitudinallyextending slot; said pinion axis of rotation extending through saidslot.

2. An electric switch comprising a first structure, a second structure,a hollow elongated blade; said structures being fixed in axial alignmentwith a gap therebetween; said blade being disposed within said firststructure and slideable along the axis thereof; said switch having aclosed position wherein said gap is open; a rack secured to said bladeand a pinion having the teeth thereof in mesh with the teeth of saidrack to move said blade along its axis and thereby operate said switchbetween said open and closed positions; an insulator having its axis inalignment with the axis of said pinion; one end of said insulator beingin operative engagement with said pinion whereby a. rotational forceapplied to the other end of said insulator will be effective to operatesaid switch; said rack being positioned between the ends of said blade;both said rack and said pinion being disposed within said blade; saidpinion having its axis of rotagss ass tion positioned perpendicular tothe longitudinal axis of said blade; said blade having a longitudinallyextending slot; said pinion axis of rotation extending through saidslot.

3. An isolated phase bus structure comprising a first hollow conductor,a second hollow conductor, a bus housing, a plurality of insulators, aswitch; said conductors being in axial alignment with a gaptherebetween; said insulators being positioned between said conductorsand said housing to center said conductors within said housing; saidswitch comprising a hollow elongated blade, a jaw, and a contactstructure; said jaw being secured to said second conductor at an endthereof; said contact structure being secured to said first conductor atan end thereof; said blade being slidably disposed within said contactstructure to move longitudinally into and out of said first conductor ina telescoping manner; said switch being movable between an open and aclosed position; said blade being positioned across said gap and inengagement with said jaw when said switch is in said closed position; arack secured to and positioned within said blade and a pinion disposedwithin said blade in operative engagement with said rack; a rotatableinsulator being interposed between said pinion and said housing wherebyactuating power may be transmitted to said switch; said longitudinalaxis being in alignment with the axis of rotation of said pinion; saidblade having a longitudinally extending slot; means connecting saidlongitudinal axis and said axis of rotation; said means extendingthrough said slot and being positioned perpendicular to the longitudinal axis of said blade.

4. An electric switch comprising a first structure, a second structure,a hollow elongated blade; said structures being fixed in axial alignmentwith a gap therebetween; said blade being disposed within said firststructure and slideable along the axis thereof; said switch having aclosed position wherein said gap is open; a rack secured to said bladeand a pinion in operative engagement with said rack to move said bladealong its axis and thereby operate said switch between said open andclosed positions; said rack being positioned between the ends of saidblade; both said rack and said pinion being disposed within said blade;said pinion having its axis of rotation positioned perpendicular to thelongitudinal axis of said blade; said blade having a longitudinallyextending slot; said pinion axis of rotation extending through saidslot; said first structure including a plurality of conducting fingershaving first ends thereof in wiping contact with the 6 exterior surfaceof said blade; said first structure also ifi cluding resilient means andat least one opening through which said first ends are urged by saidresilient means iti= to contact with said blade.

5. An isolated phase bus structure comprising a first hollow conductor,a second hollow conductor, a bus housing, a plurality of insulators, aswitch; said con= ductors being in axial alignment with a gaptherebetwee'nj said insulators being positioned between said conductorsand said housing to center said conductors within said housing; saidswitch comprising a hollow elongated blade, a jaw, and a contactstructure; said jaw being secured to said second conductor at an endthereof; said contact structure being secured to said first conductor atan end thereof; said blade being slidably disposed within said contactstructure to move longitudinally into and out of said first conductor ina telescoping manner; said switch being movable between an open and aclosed position; said blade being positioned across said gap and inengagement with said jaw when said switch is in said closed position; arack secured to and positioned within said blade and a pinion disposedwithin said blade in operative engagement with said rack; a rotatableinsulator being interposed between said pinion and said housing wherebyactuating power may be transmitted to said switch; said insulatorslongitudinal axis being stationary; said longitudinal axis being inalignment with the axis of rotation of said pinion; said blade having alongitudinally extending slot; means connecting said longitudinal axisand said axis of rotation; said means extending through said slot andbeing positioned perpendicular to the longitudinal axis of said blade;said rack being posi tioned between the ends of said blade; said contactstructure including a plurality of conducting fingers having first endsthereof in wiping contact with the exterior surface of said blade; saidcontact structure also including resilient means and at least oneopening through which said first ends are urged by said resilient meansinto contact with said blade.

References Cited in the file of this patent UNITED STATES PATENTS1,968,869 Austin Aug. 7, 1934 2,179,636 Koehler Nov. 14, 1939 2,273,069Rossman Feb. 17, 1942 2,517,435 Jensen Aug. 1, 1950

